This invention relates to a refrigerated display case.
Typically, a refrigerated display case includes a cold air discharge at one end of the case that blows cold air from the back of the case to the front of the case and over products contained therein. In addition, there is a diffuser at the top of the display case near the front that discharges cold air across the front opening of the display case. The diffuser includes a plurality of guide structures, known as straws, disposed to direct the flow of air perpendicular down the front opening of the display case. Cold air then flows to a warm air return at the bottom of the case, flowing back through a cooling circuit and out again through the cold air discharge.
Fans generally move the air through the cooling circuit. These fans are located near the bottom of the display case and draw air from the diffuser at the top of the display case to the warm air return at the bottom of the case. Usually, at least two fans are used to draw air into the warm air return from the diffuser. These fans spin generally in the same direction, say counterclockwise, on a panel that supports the fans within the case. When the fans spin in the same direction, air tends to build up over one of the fans due to the common direction of rotation of each fan. For example, fans spinning in a counterclockwise direction will build air over the left fan.
The build up of air over the fan results in the oscillation and fluctuation of air flow and an uneven air curtain across the viewing area as one side of the display case tends to receive more air than the other. Such a design is undesirable, resulting in inferior cooling of product contained within the display case as well as inefficient refrigeration. A need therefore exists for a refrigerated display case that moves air through the cooling circuit without this build up.